Drum-type pickling machine



Oct. 16, 1956 o. RUTHNER DRUM-TYPE PICKLING MACHINE Filed May l2. 1953 I IN VENTOR MMM RUT/#NER ATTORNEY United States Patent O DRUM-TYPE PICKLING MACHINE Othmar Ruthner, Vienna, Austria Application May 12, 1953, Serial No. 354,613

Claims priority, appiication Austria November'7, 1952 2 Claims. (Cl. 51-164) The invention relates to an improved drum-type lpickling machine for removing rust and scale fromv coiled strip of iron and non-ferrous metal, particularly when the coils are of high .weightand large width.

Due to the development of. steel mills and their. roll'- ing mills the piece and coil weights of the several. semi,- finished. products is continuously on the increase. This applies mainly to strip stock of iron and non-ferrous metal, which is coiled in rolling mills on reels to form coils. Whereas originally they weight of these strip coils averaged only 50-250 kg., recently coils Weighing. between 200 kg. andV 3500 kg. are increasingly employed, for economical reasons. This holds true generally for strip mills. Withthe erection of' Wide strip mills in recent years and the consequent increase of the width of the strip from 400 mm. to 2500 mm. the weightssof coils have increased to 300D-15000 kg.

When these coils of strip are hot-rolled, the highv rolling. temperature and the contact with air causes supercial oxidation. For the subsequent cold-working, of the coils they must be freed from scale first. This is effected most frequently by chemical processes, particularly by the pickiling process. In that processthe oxide layer, -calledalso scale layer, is removed by the attack of the acid and leaves a bright metal surface.

Previously it was usual to subject the several coils to a loosening process, in which the scale layer was loosened by kinking or uncoiling. the coils, andf subsequently to an acid treatment on so-called rocking. picklingf machines. The disadvantage of that plant resides in the incomplete .treatment of the coils, some points of which are not contacted by the pickling liquor so that stains appear. Moreover, it was possible only to treat coils of low Weight.

yA `considerable improvement of the pickling process was enabled by the erection of `drum-type pickling plants, where the coils were introduced into rotary drums, i-n which they uncoil and subsequently -are coiled up again as the sense of rotation of the drum is reversed. In that process each surface element of the coil is contacted by the acid so that a complete removal of scale is possible.

For wide strip, continuous pickling plants have been introduced, in which the strip is pulled by means of suitable conveyors through long pickling tanks. :Due to their large size such plants are very expensive and are not economical for a throughput of less than 8000 tons per month.

Hence, only the drum-type pickling plant enables the economical and perfect pickling of coils of high weight even in the case of small throughputs.

In the known drum-type pickling process the metal drums by means of which the coils are dipped into the pickling tank have lateral journals, one of which is connected to the drive element through a coupling. However, that system is suitable only for strip stock having coils of up -to 2 -tons in weight :and with a width of up to 500 mm. Wider and heavier coils can be pickled in these drums only with very great difliculty, due to the inadequate bearing arrangement and the danger of a de- 2,756,562 Patentedl Oct. 16, 1956 ii'ection' of' the drum. Moreover, in that plant the drum is carried in slots of the pickling tank `so that the level of the pickling liquor must be Ibelow the .bearing of the -d-rum :and the liquor can cover only part of the coil. Hence, the parts of the coil that are not covered will chafe as they uncoil and -will scratch the strip surface.

it is an object of the invention to provide an improved drum-type pickling machine for removing rust and scale from coiledl strip of iron and non-ferrous'metal, which machine is free of the `attore-described ydisadvantages'of the known apparatus.,

1F urther objects of the inventionare:

To provide an improved' drum-type pickling machine in which the drum is carried in bearings Iarranged outside of the pickling bath, isiimmersed into the pickling liquor with the` major portion of its diameter, rand enables a complete coverage of the uncoiled coils with pickling liquor;

To provide a drum-type pickling machine in which the drum is easily adjustable and portable;

To provide a drum-type pickling machine which comprises: a drum consisting of two end walls and a drum shell which extends at both ends beyond the end wall-s an-d with the projecting parts forms` rims, roll-ersfor carrying the rims, tanks for receiving the pickling liquor, and covering means for coveringthe tanks.

These and-other objectsof the invention and the novel features of the invention will be apparent from the following description taken inconjunction with the accompanying-drawing, in which.:

Fig. 1 lis a cross-sectional view of a ldrum immersed into a pi-ckling tank, with anuncoiled strip to-be pickled, Fig. 2 sectional View taken online II-II of Fig. .1., Fig. 3l a sectional view of the pickling tanks with the closing covers,` and Fig. 4 a sectional view taken on line IV-IV ofFig. 3.

Withreference to `the drawings the pickli-ng drum consists of the drum endwalls 1 and the drum shell 2, which extends beyond the drum end walls and with its projecting parts forming the rims 3, with. which the drum rests on rollers 4, l5, and 6. Of these rollers, the roller 4 is driven. by the motor 7 through the coupling` 8 and Ithe. gear unit19. The roller 6` is pivotally arranged to enable the drum to be lifted out of the pickling tank 10. The rollers carry lateral drip disks y11, which prevent the acid, which flows from rims '3 onto the rollers, from attacking the shafts of the rollers and entering the bearings of the rollers. The drum contains the coil y12 yto be pickled, which is completely immersed in the .acid when coiled up.

To connect the drum shell 2 with the drum end Walls 1, rings 13 are provided at a certain distance from both ends of the drum shell 2. In front of said rings, a number of lugs 14 (four in the example shown) are provided at a distance apart which corresponds to the thickness of the drum end walls. The disks 1 serving as drum end walls have notches 16 corresponding in number with lugs 14 and registering therewith when the disks 1 are inserted into the shell 2. After the disks 1 have been moved up to the rings 13 and turned subsequently, they are held in position by the lugs 14.

To enable the introduction `of coils 12 into the drum, the latter has an aperture 17 which is covered by a cover 18 held in position by rtwo bolts 19 stuck through two eyelets provided at the drum.

Suitably the drum-type pickling apparatus according to the invention comprises a set of several tanks, which are placed one beside the `other and into which pickling drums can be inserted. For instance, the first tank may contain the pickling liquor, the second a rinsing liquor and additional tanks may contain neutralizing or additional Washing liquors.

Each of the tanks is closed by two hinged, tankshaped halfcovers 20, which at their bearing points are provided with slotted pipes or troughs 21, connected to suction units, for sucking the fumes from the tanks. The distance between two adjacent tanks is less than twice the length of a half-cover and the latter is formed so that when the tanks are open the two adjacent half-covers of adjacent tanks overlap to collect and return into the tanks any liquid tiowing from a drum as it is moved from one tank into the other.

The mode of operation of the apparatus described is as follows:

The drum is mounted on the rollers 4, 5, 6 by means of a crane of any desired type, and should be lowered into the pickling liquor sufficiently to ensure the complete insertion of the coil to be treated. Then the drum is turned in the sense in which the coil is uncoiled, to ensure the attack of the pickling liquor at all parts of the strip. Then the drum is turned in the opposite sense to coil up the coil again. Subsequently the drum is moved from the pickling tank, e. g., into the rinsing tank. To this end the drum is lifted by the crane sufiiciently to enable the pivotal movement of the roller 6, whereafter the drum may be lifted further out of the tank and immersed into the rinsing tank. Preferably the motor with the gear unit and the rollers is mounted on a portable frame, which can be moved from one tank to another together with the drum. In that case it is not necessary to provide a separate gear unit and separate rollers for each tank. The fumes formed in the tanks are sucked oi by the suction unit described, whether the tank is closed or open. Moreover, the apparatus according to the invention thas the great advantage that the special bearing arrange- :ment of the drum eliminates the slots previously provided .in the side walls ofA the tanks to carry the drum journals. :As a result, the fumes are sucked ott completely, the acid Flevel may be as high as just below the rim of the tank :and the coil may be immersed completely in the acid. :The liquid enters between the turns of the coil aud is :effective as a lubricant as the coil is uncoiled, so that chafing and consequent scratching of the strip surface is fprevented. Moreover, the favourable bearing arrangement of `the drum and the advantageous possibility of fstiiening it enable the treatment of coils ofany width rand weight desired.

I claim:

1. An improved drum-type pickling apparatus for removing rust and scale from coiled strips of metal, which comprises a horizontally disposed drum including two ldrum end walls and a drum shell projecting at both ends fbeyond the end walls, the projecting portions of said 'drum shell forming rims at the ends of said drum, at `least three rollers for rotatably supporting said drum, said rollers -operatively being disposed within the edges of said shell with the upper portions of the shell rims resting on the peripheries of said rollers, means for driving at least one of said rollers, and pivotally mounted means journalling at least one of said rollers whereby such roller is pivctally movable into or out of the range of rotation of the drum.

2. An improved drum-type pickling apparatus for removing rust and scale from coiled strips of metal, which comprises a horizontally disposed drum including two drum end walls and a drum shell projecting at both ends beyond the end walls, the projecting portions of said drum shell forming rims at the ends of said drum, at least three rollers for rotatably supporting said drum, said rollers operatively being disposed within the edges of said shell with the upper portions of the shell rims resting on the peripheries of said rollers, means for driving at least one of said rollers, and means detachably connecting said drum shell with said two end walls and including a ring at each end of the drum shell for detachable connection therewith, and at least two lugs in front of each ring and spaced a distance which corresponds to the thickness of the drum end wall, said drum end walls having notches corresponding with said lugs to provide a rm connection after the drum end walls have been moved behind said lugs and turned between the rings and the lugs.

References Cited in the le of this patent UNITED STATES PATENTS 156,800 Kurth Nov. 10, 1874 308,844 Kuhnmunch Dec. 2, 1884 723,180 Porter Mar. 17, 1903 759,939 Thomas May 17, 1904 912,038 Seifert Feb. 9, 1909 1,331,739 Becker Feb. 24, 1920 1,845,422 Knutsen Feb. 16, 1932 1,928,950 ONeill Oct. 3, ,1933 2,099,121 Kivley Nov. 16, 1937 2,509,041 Lubenow Mayv23, 1950 2,550,077 Mills Apr. 24, 1951 FOREIGN PATENTS 423,668 France Feb. 22, 1911 

